There are powerful electrically-energized tools, for example, electromagnetic punch presses, stamping presses, spot-welding presses, and similar powerful electrical tools. Manufacturers have been hesitant or reluctant to install such electromagnetic tools, because each such tool during its brief time of operation requires a very large surge of electrical power to provide the energization for delivering the powerful movement or stroke of the tool. Such large surges of power due to multiple electromagnetic tools can overlap and thereby cause significant peaking of electrical leading, with consequent significant increases in charges from the electric utility.
For example, manufacturers have continued to use mechanically-driven presses having large rotating flywheels for delivering the required power stroke, rather than using electromagnetically energized presses. The drawbacks of such flywheel-types of presses are (i) they are bulky and require relatively large floor space, (ii) their power stroke length is fixed by the mechanical drive structures associated with the flywheel, (iii) their ballistics are mechanically fixed or predetermined by heavy flywheels such that their speed cf production cannot readily be increased, and (iv) there is not much adjustability or variability in the control of large rotating flywheels.
Replacing a significant number of flywheel-type presses, for example, twenty presses with an equal number of electromagnetic presses would normally require a considerable additional plant investment for installing increased electrical power facilities for the plant. When twenty electromagnetic presses are in operation at the same time, there is the possibility that sometimes during the workshift the operators will trigger a considerable number of these presses at about the same instant causing their power surge requirements to overlap, i.e. to cumulate, thereby placing a relatively great peak electrical demand on the electrical supply facilities of the manufacturing plant. Consequently, the electrical facilities in the plant would normally need to be of sufficiently large scale for adequately satisfying the expected peak demand or expected peak line electrical load.
Moreover, the costs of electrical energy purchased from a public utility are often dramatically increased as a result of a large "peak demand", even though the average monthly consumption of electrical power by the plant is far below this peak demand.
Also, it is to be noted that when a significant number of such powerful electrical tools are installed without a corresponding scale-up in the electrical supply facilities of the plant, then their simultaneous actuation will impose an excessive line load, causing weakened power strokes (resulting in the likely occurrence of defective parts or parts of improper quality) and/or causing incompleted power strokes due to incomplete die or punch penetration (resulting in jammed or broken tools or jammed slugs of non-ejected metal, partially punched metal or incomplete stripping away of punched metal).